Relational Algebra the basic set of operations for relational model

Relational algebra is describes the order of operations in the query

Relational algebra expression the sequence of operations in a relation algebra.

SELECT Operation

What is the result of the SELECT operation in relational algebra?

The SELECT operation in relational algebra is denoted by:

SELECT operator is Binary

degree of the relation resulting from a SELECT operation its number of attributes is the less than the degree of R

number of tuples in the resulting relation is always less than or equal to the number of tuples in R.

|σc (R)| ≤ |R| for any condition C.

The SELECT operation isn't commutative

PROJECT operation selects certain columns from the table and discards the other columns.

The Project operation in relational algebra is denoted by:

π <list1> (π <list2>)(R)) =π<list1>(R) as long as <list2> contains the attributes in <list1>

commutativity does not hold on PROJECT

The Cardinality of the relation resulting from a Project operation is …........... the cardinality of R.

πList1 (πList2 (...(πListn(R))...) ) = πList1(R)

Which Relational algebra expression is correspond to the following SQL query:

The result of the ……….operation can be visualized as a vertical partition of the relation into two relations.

σ<cond1>(σ<cond2>(σ<cond3>(R))) is equivalent to